dr. cartwright, dr. cartwright, please, no offense. i'm very familiar with all of your degrees, all of your honors and your awards that you have gotten, which are many, but frankly, if you can get a fingerprint off of a coke can or a sliding glass door, believe me a print taken in ink in a hospital would suffice. so, doyle murphy, they have thought of comparing the print taken of the foot as a baby to the body, or has mommy lost that? >> i've not heard anything about a footprint. i don't know what condition the body is in when they found it. police haven't said anything about that. i don't know what's possible at this point. >> actually, doyle, you're right. back to dr. cartwright, this child went missing around december 14th. now, granted there was a great deal of ice and snow, which is what hindered police from searching this area sufficiently the first time. at this point, the body would likely be so degenerated, they couldn't make even a fingerprint i.d. wouldn't you assume most of the soft tissue is gone? >> it really does depend

dr. robert cartwright, an expert in his field, joining us out of atlanta. dr. cartwright, these polygraphs, lie detectors, they're based on a physical reaction. how does it work medically? >> well, certainly, when you have stress, which would indicate perhaps deception, it creates changes in your physical makeup. your heart rate can change, blood pressure can change. your ekg in terms of your heart waves can change. so that's really what they're looking for. >> and dr. cartwright, there's no real way that i know of that you can control those involuntary bodily reactions. >> not certainly for an average person, somebody in misty croslin's position, i don't think that would be possible. now, apparently, there are people in, you know, cia, fbi, those types of people, that have been trained to break those. but for routine people, no. >> of course i guess you could dope yourself up on sedatives so you'd be so zonked out you'd just be flat. but i would be afraid i would screw up the answers if i had taken some kind of medication. would that work? >> well, certainly, t